My GMail account has become a major issue in the new Outlook.

@Warren Nelson said

I've tried to reconnect my GMail account in the new version of Outlook for 3 days and nothing has worked.

All I can suggest is reset the whole environment.

Remove the accounts, Nuke your New Outlook profile, and re-add the accounts from scratch.

• View -> View settings -> Accounts > Your accounts
• Pick an Account and [Manage]
• [Remove]
• (o) Remove from all devices (If you see it)

Then to Nuke the profile see the answer by "Hornblower409 Dec 11, 2025" in
https://learn.microsoft.com/en-us/answers/questions/5655980/outlook-starting-error-repair-reinstall-reset-does

Add back the account using these instructions:
https://support.microsoft.com/en-us/outlook/getstarted/add-a-gmail-account-to-outlook-for-windows

If that doesn't help, please come back and provide some details on where in the process you are hitting a snag.